Elastic-fluid turbine.



PATENTED' DEG. 11,1906,

G. A'. BAGKSTROM. ELASTIC FLUID TURBINE. APPLICATION FILED NOV. 21. 1962. RENEWED KAY-16, 100s.

2 M 4 flame 5.

I A @W/f 1n: HCRRIS PETERS co., wAsHmuroN, n. c.

UNITED STATES PATENT OFFICE.

CHARLES A. BACKSTROM, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO THE BACKSTROM-SMITH STEAM TURBINE & MANUFACTURING COMPANY,

OF MILWAUKEE, WISCONSIN,

A CORPORATION OF WIsCoNsIN.

ELASTIC-FLUID TURBINE.

Specification of Letters Patent.

Patented Dec. 11, 1906.

T0 (1, whom it may concern.-

Be it known that I, CHARLES A. BACK- sTRoM, a citizen of the United States, residing at Milwaukee, county of Milwaukee, and State ofWisconsin, have invented new and useful Improvements in Elastic-Fluid Turbines, of which the following is a specification.

My invention relates to improvements in elastic-fluid turbines.

The object of my invention is to provide means for regulating the supply of motive fluid in proportion to the load without impairing the efliciency of the engine.

The invention is especially adapted to be used in axial-flow turbines.

In the following description reference is had to the accompanying drawings, in which Figure 1 is a detail sectional view drawn to a plane common to the axes of the shaft and one of the tubular valve-chambers. Fig. 2 is a transverse sectional view drawn on line w m of Fig. 1'; and Fig. 3 is a complete transverse sectional view of the shaftdrum, sleeve, and outer casing, drawn on a reduced scale, on line w a: of Fig. 1.

Like parts are identified by the same reference characters throughout the several views.

1 is a shaft drum or cylinder. 2 designates vane-holding rings mounted on the drum, with interposed spacing-rings 7. The vanes 4 are sup orted from the side faces of the rings 2 and project therefrom on lines parallel with the axis of the turbine. These parts constitute the movable member of the turbine.

An inclosing casing 10 of the stationary member is provided with inwardly-projecting annular walls or flanges 11 and 12, which support a nozzle-ring 13, the space between the walls 11 and 12 being subdivided by partitions 14 to form segmental nozzle-chambers 9. The nozzle-ring 13 is provided with apertures 16, which constitute nozzles through which the fluid is delivered against the vanes. The walls 11 and 12 are reinforced by connecting-blocks 15 at suitable intervals.

In the construction shown one wall 11, which supports each nozzle-ring, extends into close proximity to the side wall of the corre. sponding vane-supporting ring 2, this wall and the ring serving as a transverse partition around which the motive fluid is directed in suitable valve-controlled passages leading through the nozzles of each nozzle-ring, one

such passage being shown in longitudinal sec- 'set of partition-valves 21, subdividing the valve-chamber into compartments. In closed position these valves cover the outlet-ports 23. In open position they are adjusted between the inlet and outlet ports, when the motive fluid is permitted to pass from one compartment of the valve-chamber through an inletport 22, anozzle-Chamber 9, and the nozzles pertaining thereto to the vanes and from the space 24 on the delivery side of the vanes through a port 23 to the next compartment of the valve-chamber, from which it passes through the corresponding inlet-port 22, nozzle-chamber, and nozzles to the next set of vanes, and so on, as indicated in Fig. 1 by a dotted line and arrow-points, to the exhaust end of the turbine.

The valves of each chamber are connected by 2. common valve-actuating stem 25, whereby they are simultaneously shifted to either open or closed position, and as each valve chamber and its valves absolutely control the delivery of motive fluid to each nozzle-chamber the opening or closing of the valves in any one chamber does not affect the density or pressure of the motive fluid passing through any of the other chambers. The turbine is thus divided into as many longitudinal sections as there are valve-chambers, and each section is independent of the others and provided with nozzles of progressively-increasing capacity, proportioned to give an adiabatic expansion of the fluid passing therethrough. The space 24 on the discharge side of each series of vanes is annular and common to all sections, but the motive fluid passing through any one section is prevalves, mechanism for so doing being shown and described in a separate divisional application, filed December 15, 1902, Serial No. 135,252. 'The specific arrangement of the vane-supporting rings 2 and their relation to the nozzle-rings 13 and supporting-flanges 11 and 12, whereby the turbine is transversely partitioned by rings on the movable member revolving in approximate side contact with annular walls on the stationary member, together with the provision of motive fluid passages which extend outside the field of movement of the rotary member in passing the transverse partitions, is also made the subject of a divisional application, filed December 29, 1902, Serial No. 136,982. While, therefore, it has been expedient to show and describe features of construction pertaining to said divisional applications, it will be understood that the invention herein claimed may be applied to any form of turbine in which the motive fluid is made to act successively, in view of the fact that any means for cutting off the supply of motive fluid to each of a sequence of nozzles or delivery apertures in the same passage will fall within the scope of this invention. In stating that the flow of the fluid to each of a plural series of vanes or through each of a sequence of sets or groups of nozzles is controlled by the valves or equivalent cut-off mechanism it is not meant that the delivcry of motive fluid to every series of vanes or through every set of nozzles in the turbine is controlled by valves or cutofl devices. In most turbines, however, it will be found desirable to provide valves for controlling the delivery of motive fluid through all the nozzles in order to maintain the highest efliciency.

It will be observed that the division of the turbine into longitudinal sections is accomplished by providing means for closing one longitudinal series of nozzles whileleaving another series of similar nozzles open, the delivery of steam through the nozzles of each series being absolutely controlled by the valves themselves, so that it is unnecessary to provide longitudinally-extending division-walls to preserve the independence of the sections.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a turbine, a movable member having vanes arranged in plural series; a stationary member subdivided into sections, and having each section provided with means for direct ing the motive fluid against the vanes of each series; and a set of valves for each section, each controlling the passage of fluid from one series of vanes to another; the valves of each set being adjustable independently of the others.

2. In a turbine, a movable member having vanes arranged in plural series; nozzles for directing the motive fluid against the vanes valve-chambers extending axially across the paths of the vanes, and provided with ports adapted to permit the passage of motive fluid through the nozzles; each valve-chamber communicating with one grouplof nozzles for each series of vanes; and a set of interconnected valves in each valve-chamber, controlling the passage of fluid through said ports.

3. In a turbine, a movable member provided with series of vanes; a stationary mem ber having segmental nozzle-chambers provided with nozzles for directing fluid against the vanes valve-chambers having ports communicating respectively with one nozzlechamber for each series of vanes and with thedelivery-space beyond the vanes; valves controlling the passage of fluid through each valve-chamber, and serving as partitions to subdivide the chamber between the ports when the latter are open for the passage of fluid.

4. In a turbine, a movable member having vanes arranged in plural series alon a common axis a set of segmental nozzIe-chambers for each series of vanes; valve-chambers each provided with suitable ports, and cooperatively arranged with one nozzle-chamber of each set, to form a continuous fluid-pas sage through the successive series of vanes; and a set of interconnected valves in each valve-chamber, controlling the fluid-passage.

5. In a turbine, a movable member having vanes arranged in plural series along a common rotary axis; an annular set of segmental nozzle-chambers for each series of vanes; valve-chambers provided with suitable ports, each cooperatively arranged with one nozzle-chamber of each set to form a continuous fluid-passage through the successive series of vanes; and a set of interconnected valves in each valve-chamber, controlling the fluidpassa e, the valves of each chamber being capab e of adjustment independently of those of other chambers.

6. In a turbine, a movable member provided with a plural series of vanes; a stationary member arranged with reference to the movable member to form a plurality of passages crossing successive serles of vanes, and with each such passage formed to direct motive fluid against the vanes in substantially the same direction of impact; valves in each passage, one adjacent to, and controlling the flow of motive fluid through each series of vanes, and means for opening the valves of any desired number of passages, While leaving those of the remaining passages closed.

7. In a turbine, a movable member provided With a plural series of vanes; a stationary member arranged with reference to the movable member to form a series of like passages for motive fluid, crossing the paths of the vanes in substantially the same direction, and also arranged to form annular spaces common to all the passages; valve mechanism adapted to control the flow of motive fluid in each passage; said valve mechanism being arranged to cut off the fluid at intervals in each passage Without affecting the flow in the other passages.

In testimony whereof I'aflix my signature in the presence of tWo Witnesses.

CHARLES A. BACKSTROM. Witnesses: CHAs. B. PERRY, LEVERETT 0. WHEELER. 

